1. Field of the Invention
The present invention concerns a method for respectively generating stereo signals for at least two sound sources. Moreover, the present invention concerns a corresponding acoustic system for generation of stereo signals. The present invention in particular concerns hearing devices such as hearing aid devices.
2. Description of the Prior Art
A method for generating respective mono (monaural) signals for each of multiple sound sources is known from the essay by J. Benesty, Y. Huang: Adaptive Signal Processing: Berlin, N.Y., pages 195-23, 2003. The BSS methods (blind source separation) described therein can separate and individually reproduce spatially-separate but temporally-overlapping sources. Such a BSS method can be used, for example, as a binaural feed or especially for a binaural directional microphone, whereby a microphone signal from the right hearing device is used as well as a microphone signal from the left hearing device.
A problem that still has yet to be solved is that the BSS method provides only a mono signal for each of the separate sources. If the hearing device user were to be identically provided with this signal at both hearing devices, the user could in fact perceive the sources with very good separation, but spatial localization of the sources would not be possible. For this purpose, the right and left signals would have to be differentiated at the inter-aural level and delay differences that are typical for natural signals would have to be introduced.
Alternative methods to the BSS methods for binaural directional microphony exhibit a very limited capability and for this reason (as well as due to the usually absent wireless connection between hearing devices) are not used.